Not Applicable
Not Applicable
1. Field of the Invention
The present invention relates to a filling apparatus.
2. Description of Related Art
Conventionally, in a filling apparatus for producing packaging containers filled with liquid food, such as milk or soft drink, a web-like packaging material is continuously formed into a tubular shape, while being transported, and then the tubular portion of the packaging material is filled with liquid food to thereby produce a packaged product.
FIG. 1 is a perspective view of a conventional filling apparatus.
In FIG. 1, reference numeral 11 denotes a packaging material. The packaging material 11 in the form of a roll 12 is loaded into the filling apparatus, is fed into the filling apparatus by means of an unillustrated feeder and is transported in a web-like form within the filling apparatus.
Subsequently, the web-like packaging material 11 is gradually formed into a tubular shape by means of an unillustrated forming ring and other components. The thus formed tubular portion of the packaging material 11 is longitudinally sealed by means of an unillustrated longitudinal sealing apparatus. While being transported downward, the packaging material tube is filled with liquid food supplied from above via a filling pipe 13. Next, while being nipped from both sides, the packaging material tube is laterally sealed at predetermined intervals by means of an unillustrated lateral sealing apparatus, thereby forming containers 14 each in the form of, for example, a pillow or a bag.
Subsequently, an unillustrated cutting apparatus cuts the packaging material tube at the laterally extending seal portions S1, thereby separating the containers 14 from one another. An unillustrated forming apparatus forms each of the containers 14 into a predetermined shape through bending along preformed creases, thereby completing a packaging container 15.
Since the packaging material tube has a substantially circular cross section, the transported packaging material tube presents difficulty in positioning. For example, forces received from the forming ring cause the packaging material tube to turn in the direction of arrow A1 or A2, whereby the longitudinally extending seal, i.e. overlap portion S2, deviates from a predetermined position. When the container 14 is shaped to form the finished packaging container 15 while the overlap portion S2 is improperly positioned, preformed creases of the packaging material 11 fail to positionally coincide with actual creases, resulting in a poor appearance of the packaging container 15.
FIG. 2 is a plan view of a container formed with an overlap portion located at a predetermined position. FIG. 3 is a plan view of a container formed with an overlap portion which has deviated from a predetermined position.
In FIGS. 2 and 3, reference numeral 14 denotes a container in an early stage of forming; reference numerals 14a and 14b denote lugs; reference numeral S1 denotes a lateral seal portion; reference numeral S2 denotes an overlap portion; and reference numerals m1 and m2 denote creases preformed in the packaging material 11 (FIG. 1) and along which the lugs 14a and 14b bend. As shown in FIG. 2, when the container 14 is formed with the overlap portion S2 properly located at the predetermined position, the creases m1 and m2 each assume the form of a straight line. Thus, the lugs 14a and 14b can be bent along the creases m1 and m2.
However, as shown in FIG. 3, when the container 14 is formed with the overlap portion S2 removed from the predetermined position, the creases m1 and m2 assume the form of segments out of alignment. As a result, the lugs 14a and 14b cannot be bent along the creases m1 and m2 and, instead, the lugs 14a and 14b bend along creases n1 and n2.
In order to cope with the above-described problem, a paper guide is disposed along an unillustrated transport path on which the web-like packaging material 11 travels. The paper guide is pressed against an edge portion of the packaging material 11 so as to move the packaging material 11 perpendicular to the direction of transport, thereby adjusting the position of the overlap portion S2 to coincide with the predetermined position.
However, in the conventional filling apparatus, because the paper guide is pressed against an edge portion of the packaging material 11, the edge portion is consequently damaged.
The packaging material 11 is formed through longitudinally cutting an unillustrated wide web at a plurality of positions. When variations in the width of the packaging material 11 arise due to positional cutting error, even the positional adjustment of the overlap portion S2 fails to cause positions of creases m1 and m2 to coincide with the positions of the creases n1 and n2.
FIG. 4 illustrates creases preformed in the packaging material. FIG. 5 is a sectional view of a packaging material tube.
In FIGS. 4 and 5, reference numeral 11 denotes a packaging material; reference numerals 11a and 11b denote edges of the packaging material 11; reference numerals m1 and m2 denote lateral creases preformed in the packaging material 11; and reference numerals m11 to m14 denote longitudinal creases preformed in the packaging material 11. When there is no positional cutting error, the width of the packaging material 11 is constant. However, when an error in cutting position occurs, variations in the width of the packaging material 11 result.
As a result, the distance xcex1 between the edge portion 11a and the crease m11 varies. Even when the position of the overlap portion S2 is adjusted in the course of formation of a packaging material tube 41 as shown in FIG. 5, the creases m1 and m2 fail to coincide with the creases n1 and n2 (FIG. 3), resulting in a poor appearance of the packaging container 15 (FIG. 1).
Therefore, an object of the present invention is to solve the above-described problems in the conventional filling apparatus and to provide a filling apparatus capable of establishing positional coincidence between creases preformed in a packaging material and actual creases to thereby improve the appearance of the packaging container.
To achieve the above object, the present invention provides a filling apparatus including a light source for irradiating, with light, a portion of the outer circumferential surface of a packaging material including a longitudinal overlap; light detection means for issuing a sensor output upon reception of light emitted from the light source and reflected from the outer circumferential surface of the packaging material tube; and overlap location detection means for detecting the position of the overlap as a peak in the sensor output.
Light reflected from an end portion of the packaging material exhibits greater intensity and appears as a peak in sensor output from the light detection means. Accordingly, a location on the packaging material tube which causes emergence of a peak in the sensor output is detected as an overlap portion.
Since light reflected from the eNd portion of the packaging material is greater in intensity than light reflected from other portions of the packaging material, the face of a packaging container does not cause noise. Thus, the overlap portion can be detected with high accuracy.
Upon completion of a packaging container, a user can judge from the position of the overlap whether or not forming has been performed properly. Thus, sampling a packaging container from a production line becomes unnecessary, thereby simplifying the work of judging whether or not forming has been performed properly, and thus reducing the cost of production of a packaging container. Also, all packaging containers can be checked so as to see whether or not they have been formed properly.
Mere digitization of sensor output from the light detection means suffices, without need to first take an image and then process data regarding the taken image, thereby reducing the cost of manufacture of a filling apparatus. Since there is no need for direct contact with the packaging material, the overlap portion can be detected with high accuracy.
In another embodiment the filling apparatus of the present invention comprises packaging material tube formation means for forming a packaging material tube from a web-like packaging material; a guide roller rotatably disposed upstream of the packaging material tube formation means with respect to the transport direction of the packaging material and adapted to guide the packaging material; overlap portion detection processing means for detecting an overlap portion of the packaging material tube; and centering processing means for moving one end of the guide roller on the basis of the result of detection by the overlap portion detection processing means.
Since the position of an edge of the packaging material is changed, the overlap portion can be moved accordingly. That is, the position of the overlap portion can be adjusted such that the overlap portion is maintained in a predetermined position.
Also, creases preformed in the packaging material can be made to coincide with actual creases, thereby improving the appearance of a packaging container.
In still another embodiment, the filling apparatus of the present invention includes packaging material tube formation means for forming a packaging material tube from a web-like packaging material; a guide roller rotatably disposed upstream of the packaging material tube formation means with respect to the transport direction of the packaging material and adapted to guide the packaging material; a support mechanism for movably supporting one end of the guide roller; and a fulcrum mechanism for pivotably supporting the other end of the guide roller.
In this latter embodiment, when one end of the guide roller is moved, the packaging material is caused to move axially on the surface of the guide roller according to the amount of movement of the one end of the guide roller; i.e., the packaging material can be moved perpendicular to the direction of transport of the packaging material. Since the positions of the opposite edges of the packaging material are moved, the overlap can be moved accordingly, i.e., the position of the overlap portion can be adjusted.
Because adjustment of the position of the overlap does not involve the pressing of paper guides against edges of the packaging material, potential damage to the edges of the packaging material is avoided.
In the filling apparatus of the present invention one end of the guide roller is preferably moved along a direction parallel with the transport plane of the packaging material which approaches the guide roller. Since one end of the guide roller is moved along a direction parallel with a transport plane of the packaging material approaching the guide roller, there is no great change in the transport of the packaging material.
Further, it is preferred that one end of the guide roller be removably disposed in the support mechanism. Since one end of the guide roller is removably disposed, the work of loading the filling apparatus with the packaging material is simplified.